Vitamin D Binding Protein (Gc) Allele Variation Effects Response to Vitamin D Treatment
- Conditions
- Vitamin D Status
- Registration Number
- NCT00650780
- Lead Sponsor
- Creighton University
- Brief Summary
We have just completed a randomized, clinical trial of 100,000 IU Vitamin D3 given as a single dose at the beginning of winter. We found a wide range of responses to the dose. This study proposes that genetic differences account for some of the variation in response of 25(OH)D levels after treatment with oral Vitamin D.
- Detailed Description
We suspect that the wide range of response is effected by other factors such as variation in Vitamin D binding protein (the major transporter of Vitamin D metabolites).
Gc, also known as Vitamin D binding protein (DBP), group specific component, or Gc globulin, is a 52-58 kDa multifunctional plasma protein, synthesized in the liver. The gene encoding for Gc is located on chromosome 4, and three common co-dominant alleles give rise to three phenotypes (Gc1s, Gc1f, and Gc2). Gc binds actin, recruits neutrophil leukocytes and converts into a macrophage- and osteoclast- activating factor. It also is the major transporter of Vitamin D and its' metabolites. Lauridsen et al. showed that Gc phenotype correlates with 25(OH)D levels in a group of postmenopausal women.
This study proposes that Gc phenotype accounts for some of the variation in response of 25(OH)D levels after treatment with oral Vitamin D.
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- All
- Target Recruitment
- 29
- Must be willing to participate with an additional blood draw.
- Must have been in the previous study.
- Will not be eligible if not a part of the previous study
Study & Design
- Study Type
- OBSERVATIONAL
- Study Design
- Not specified
- Primary Outcome Measures
Name Time Method Gc concentration and phenotype at 1st visit
- Secondary Outcome Measures
Name Time Method
Trial Locations
- Locations (1)
Creighton University
🇺🇸Omaha, Nebraska, United States